Servo motor control labeller

In a labeller of the type in which labels with self adhesive backings are mounted on a backing web which is fed from a feed supply to a take-up with the labels being dispensed by drawing the web around a peeling surface, whereby the labels being stiffer than the backing web are separated from the web and are moved to touch down on a surface to be labelled being fed thereby, a servo motor for driving said label backing web to advance the labels mounted thereon, a first pulse generator adapted to be driven from the feed of a surface to be labelled and generating pulses representative of predetemined increments of surface advance, a pulse generator connected to said servo motor to produce pulses representative of predetermined increments of label advance which are equal to the increments of surface advance and control means for said servo motor operable upon receiving an instructing signal to label delivered at a preselected point of surface advance towards the labeller to accelerate said servo motor up to speed so that the pulse output of said second pulse generator matches the pulse output of said first pulse generator whereby in operation the label to be dispensed which is stationarily located at a predetermined start position relative to said peeling surface is brought up to the speed of the surface to be labelled for touch down of the label at a predetemined point on the surface with the label and surface moving at the same speed, and decelerator means responsive to label feed following touch down of the label being dispensed operable, in the absence of a further label instructing signal to feed the next subsequent label, to decelerate said servo motor to bring said next subsequent label to be dispensed to rest at said predetermined start position.

In a labeller in which a rotary drive is translated into label feed to apply a label to a surface being fed thereby, a servo motor for driving said rotary drive, a first encoder to be driven by the feed of the surface to be labelled to produce output pulses corresponding to predetermined increments of surface feed, a second encoder driven by said servo motor and producing output pulses corresponding to predetermined increments of label feed which are equal to said predetermined increments of surface feed, and a speed control system for said servo motor, said speed control system comprising means for driving said servo motor in response to pulses derived from said first encoder and their count relative to the count of pulses generated by said second encoder and comprising counter means connected directly to said second encoder, a labelling control system interposed between said first encoder and said counter means, said labelling control system comprising an accelerator, means responsive to input data to produce an instruct to label signal after a predetermined number of first encoder pulses following a home pulse to activate said accelerator, said accelerator being connected to receive input pulses from said first encoder to produce output pulses in response thereto at a progressively increasing rate until the accelerator output pulse are in step with the encoder input pulses, said accelerator being connected to apply its output pulses to said counter means until after its output pulses are in step with its encoder input pulse means and to thereafter connect said first encoder pulses directly to said counter and deactivate said accelerator, a decelerator connected to receive input pulses from said first encoder to produce output pulses and apply them to said counter at a progressively decreasing rate until stopped, and means responsive to label feed for activating said decelerator and disconnecting said first encoder from said counter.

In a labeller in which a rotary drive is translated into label feed to dispense a label onto a surface being fed therepast, a servo motor for driving said rotary drive, a first surface feed measuring encoder to be driven by the feed of the surface to be labelled to produce pulses corresponding to predetermined increments of surface feed, a second label feed measuring encoder driven by said servo motor and producing pulses corresponding to predetermined increments of label feed which are equal to said predetermined increments of surface feed, a speed control system for said servo motor, and a labelling control system for controlling said speed control system, said speed control system comprising an up/down counter connected to said first encoder through said labelling control system to count pulses output from said labelling control system and connected to count directly the output pulses of said second servo motor encoder, the arrangement being such that said counter produces an output proportionate to the difference in the number of counts received from said second encoder and from said labelling control system which is in one direction when the labelling control system counts are greater than the servo motor encode counts and in the opposite direction when the servo motor encode counts are greater than the labelling control system counts, a digital to analog converter operatively connected to said counter to produce an output voltage having a magnitude and polarity corresponding to the magnitude and direction of the counter output, a servo amplifier for driving said servo motor, means operatively connecting said digital to analog converter to said servo amplifier, the arrangement being such that said servo motor is driven in a manner such as to effectively match the count of the output pulses from said second servo motor encoder to the count of the pulse from said labelling control system delivered to said counter, said labelling control system comprising an accelerator, means responsive to an instruct to label signal to activate said accelerator, said accelerator being connected to receive input pulses from said first encoder to produce output pulses in response thereto at a progressively increasing rate until the accelerator output pulse are in step with the first encoder input pulses, said accelerator being connected to apply its output pulses to said counter until after its output pulses are in step with its first encoder input pulse, means activated subsequent to said accelerator output pulses reaching in step relation with its first encoder input pulses to thereafter connect said first encoder pulses directly to said counter and deactivate said accelerator, a decelerator connected to receive input pulses from said first encoder to produce output pulses and apply them to said counter at a progressively decreasing rate until stopped, and means responsive to label feed for activating said decelerator and deactivating said means connecting said surface feed first encoder directly to said counter.

In a labeller of the type in which labels with self adhesive backings are mounted on a backing web which is fed from a supply to a take-up with the labels being dispensed by drawing the web around a peeling surface whereby the labels being stiffer than the backing web are separated from the web and are moved to touch down on a surface to be labeled being fed past the labeller, a surface feed measuring encoder to be driven by the feed of the surface to be labelled to produce pulses corresponding to predetermined increments of surface feed, a servo motor for driving said label backing web to advance the labels mounted thereon, a label feed measuring encoder driven by said servo motor and producing pulses corresponding to predetermined increments of label feed which are equal to said predetermined increments of surface feed, a speed control system for said servo motor and a labelling control system for controlling said speed control system, said speed control system comprising an up-down counter connected to count directly the output pulses of said servo motor encoder and connected to said surface feed measuring encoder through said labelling control system, the arrangement being such that said counter produces an output proportionate to the difference in the number of counts received from said servo motor encoder and from said labelling control system which is in one direction when the labelling control system counts are greater than the servo motor encoder counts and in the opposite direction when the servo motor encoder counts are greater than the labelling control system counts, a digital to analog converter operatively connected to said counter to produce an output voltage having a magnitude and polarity corresponding to the magnitude and direction of the counter output, a servo amplifier for driving said servo motor, said servo amplifier being responsive to said output voltage to produce a servo motor speed such as to effectively match the count of the output pulses from said servo motor encoder to the count of the pulses from said labelling control system delivered to said counter, said labelling control system comprising an accelerator, means responsive to input data to produce an instruct to label signal after a predetermined number of surface feed encoder pulses following a home pulse to activate said accelerator, said accelerator being connected to receive input pulses from said surface feed encoder to produce output pulses in response thereto at a progressively increasing rate until the accelerator output pulses are in step with the encoder input pulses, said accelerator being connected to apply its output pulses to said counter until after its output pulses are in step with the encoder input pulses, means activated subsequent to said accelerator output pulses reaching in step relation with its encoder input pulses connect said surface feed encoder directly to said counter and deactivate said accelerator, a decelerator connected to receive input pulses from said surface feed encoder to produce output pulses and apply them to said counter at a progressively decreasing rate until stopped, and means responsive to label feed for activating said decelerator and deactivating said means connecting said surface feed encoder directly to said counter.

Labelling apparatus comprising a labeller actuated by a rotary drive label feed, sensing means for providing an end label feed signal following dispensing of a label, means to feed a surface to be labelled at a constant speed past said labeller, a first encoder driven by said surface speed means and producing output pulses following a home pulse corresponding to predetermined increments of surface feed, means for providing an instruct to label signal at a predetermined number of pulses after said home pulse, a servo motor for driving the rotary drive of said labeller, a second encoder driven by said servo motor and producing output pulses corresponding to predetermined increments of label feed equal to said predetermined increments of surface speed, a speed control system for said servo motor and a labelling control system for controlling said speed control system, the arrangement being such that upon an instruct to label signal being given at said preselected number of pulses of said first encoder following said home pulse said labelling control system operates to control said speed control system to progressively accelerate said servo motor from a stationary condition to bring said second servo motor encoder pulses into synchronism with said first encoder pulses after a predetermined number of first encoder pulses to dispense a label into said surface at said predetermined point with the label travelling at the same speed as the surface to be labelled, and upon an end label feed signal being given by said label feed sensing means said labelling control system operates to control said speed control system to progressively decelerate said servo motor back to said stationary condition after a predetermined number of first encoder pulses.

Apparatus for applying labels to a surface to be labelled in accordance with a predetermined scheme comprising a labeller adapted to dispense labels with self-adhesive backings mounted on a backing web, the labels having a stiffness greater than said web, said labeller providing a downwardly inclined label feed path terminating in a peeling surface, rotary driven means for drawing the web around said peeling surface and return same to a take up roll whereby the labels being stiffer than said web progressively separate from said web and continue their downwardly inclined travel at web speed until the leading label edge touches down on a surface to be labelled being fed beneath said delivery ramp in the direction of label feed, means for feeding a surface to be labelled beneath said peeling surface to receive a label, a first encoder driven by said surface means and producing a home pulse representative of a start position of a predetermined feed cycle of said surface feed means and a predetermined number of feed advance measuring pulses between the difference in the number of pulses received from said labelling control system and said second encoder to drive said servo motor to reduce the difference to zero, the arrangement being such that the servo motor is operated to dispense a label so that it touches down at the requisite predetermined point on the surface to be labelled with the label and surface travelling at the same speed, and thereafter label feed is brought to zero with the next subsequent label in position for dispensing when called for by said data input controller.